Eye tracking is known per se and is used for example in behavioural research or market research when it is necessary to examine on what visual points a gaze of a person or even of an animal rests, when, how long and/or in what sequence, or how the gaze or a gaze direction moves between different visual points. This can give information for example about where and how a supplier should place goods for sale most favourably in order to be sure of the attention of the passers-by.
In the case of methods known from the state of the art for eye tracking, scene images are recorded which reproduce a scene which is visible for a test subject—the word can stand subsequently also both for a person and an animal in the present document—and for which purpose for example a camera, which is fixed on the head of the test subject and thus moves with the head, can be used. At the same time, an eye position and hence a gaze direction of the test subject is detected, which can take place for example with the help of cameras directed towards the eyes of the test subject using suitable image evaluation methods. After calibration of such an eye tracker, conclusions can then be made, even with changing eye positions and head positions, respectively about a visual point in the scene images, the term visual point—this applies also for the subsequent description of the invention and of the embodiments—designating a point in the scene image upon which the gaze of the test subject rests at a moment to which the scene image is assigned.